End closures for cans and other containers and, more specifically, those of the so-called "easy-open" type are, of course, well known in the art. Typically, they include an end wall having a removable panel defined therein by a rupturable primary score which, upon severance and removal of the panel, provides a dispensing aperture. Generally, score rupture and panel removal are both effected by use of a pull tab having a nose portion at one end and a handle portion at its opposite end. The tab is so mounted on the panel as to be pivotable into contact adjacent the score, so as to initiate severance thereof, and to thereafter facilitate tearing of the panel away from the remainder of the end wall.
Often, the removable panel has formed therein a rupturable ancillary score which is employed to facilitate pivoting of the tab and score initiation and, in the case of a container under pressure or vacuum, to afford initial venting. As typified by the can end closure construction illustrated in U.S. Pat. No. 3,863,801, such an ancillary or "moustache" score is formed in the removable panel so that it passes inwardly of the tab securing means and extends generally laterally therefrom. However, this score configuration has been found generally unsuitable for a can end closure of the type which has a double-folded band formed in the removable panel adjacent the primary score to afford raw edge protection (see, for example, the can end closure described in U.S. Pat. No. 3,696,961). While moustache scores are satisfactory in terms of facilitating tab pivoting, score initiation and initial venting, their utilization causes a relatively large portion of the panel, i.e., the panel area defined between the primary and ancillary scores, to be pivoted downwardly upon manipulation of the tab to effect rupture initiation of the primary score. This, in turn, tends to produce a relatively long arc of initial score severance as a result of which the initial rearward force applied (to effect continued tearing of the score) will be distributed over an extended area of the panel. This reduces the effectiveness of the initial tear force applied and, in turn, necessitates the use of an undue amount of effort to effect panel removal.
In addition, the downward pivoting of a relatively large portion of the panel can be an extremely undesirable feature where the closure is used on containers for foodstuffs, such as puddings and the like, since the bent panel portion will function as a scoop, carrying some of the packed product with it as it is detached from the can. Not only is it aesthetically unpleasing and a cause of splattering, but it also poses a potential safety hazard, particularly to young children, since it entices them to lick the product off the severed panel. Although the panel may be provided with a "safety" edge, i.e., the double-folded band, the raw edge of the panel cannot be entirely shielded, and so some possibility of potential injury would generally exist.
Accordingly, it is an object of this invention to provide a novel can end closure which affords desirable opening characteristics and maximizes the effectiveness of the applied, initial rearward tearing force.
It is also an object of this invention to provide such a novel container end closure which also minimizes potential safety hazards to consumers and eliminates the problem of product pickup on the detached panel.
It is a further object of this invention to provide such a novel container end closure which is simple, highly effective, and of relatively inexpensive construction.
It is a more particular object of this invention to provide a novel container end closure of the "easy-open" type having the foregoing attributes and characteristics.